In a paintball gun, projectiles are admitted into a gun barrel from a magazine through a radial hole in the upper region of the barrel. Compressed air is then delivered between the breech of the gun and the projectile, and the expansion of the gas propels the paintball down the gun barrel. The alternate opening of the paintball entry port and the gas admitting port is controlled by a bolt assembly that, in a recoiled position, allows a paintball to drop into the gun barrel and in a firing position move that paintball forward and closes the paintball admitting port while at the same time opening the gas delivery port. The envelope of a paintball is commonly made of soft, pliable material that can be easily torn. When a paintball is jammed into the gun barrel or is only partially passed through the paintball admitting port, the bolt tends to chop or crush the paintball smearing viscous paint inside the firing mechanism and rendering the gun inoperable until it has been thoroughly cleaned.
The prior art had produced some anti-chopping bolt assemblies that are built within the bolt and require actuation through some radially moving parts. The complexity of the anti-chopping and crushing mechanism of the prior art tends to reduce gun reliability. Moreover, the axial unbalance of the mechanism tends to increase wear and affect the life of the gun.
This invention results from an attempt to devise a simple, reliable and balanced mechanism for avoiding chopping or crushing a jammed paintball.